Storing Flashlight in hot area?

My favorite small flashlight is a Surefire G2, which uses 123 cells. I'd like to keep a spare in the center console of my car (glove box is too far to reach), but the temperatures get pretty hot inside there- hot enought to liquify chocolate or Chapstick. We joke that the adjacent cup holder can be used as a fondu pot.

The light itself should be ok, but what will happen to the batteries? Reduced storage life is something I can accept, but leakage, fires, or explosions are not ok.

Predictions?

Primary lithiums tolerate heat, and cold, very well.

Much better than alkalines.

You're OK.

I thought primary lithiums are susceptible to venting in hot ambient temperatures. The interior of a parked car directly exposed to sunlight during summer can easily exceed 120 degrees.

Lithium primaries will tolerate temperatures of about 60 degrees C, which is 140 degrees Farenheit. I don't think they will "vent with flame," especially single cells, but CR batteries have much higher self-discharge rates at those kind of temperatures.

Shouldn't the glove box be a bit cooler? I lived in the desert for a while and it seemed like stuff in the glove compartment was usually a little less hot than the rest of the car, and we're talking 100+ degree days.

Alternative: Keep the light in a Thermos bottle. Seriously. Dewar flasks are excellent at keeping temperature differentials.

I doubt you car raches 60C because that is the burn threshold for humans, not just uncomfortable, but harmful. If you have any concerns then get a properly sized dewar type thermos.

Sable said:

Alternative: Keep the light in a Thermos bottle. Seriously. Dewar flasks are excellent at keeping temperature differentials.

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That's very clever, thanks for the tip. :goodjob:

I sometimes store mine in an insulated bag with my phone

There is nothing to worry about at all.

Nothing at all.

There will be no fire, none.

We keep our first aid kit and Inova XO3 in a small Igloo cool box.

We here in Malaysia have no such problems with the heat. Laminating your windows with window tint could also help reduce most of the UV penetrating into your car which then makes the insides much cooler, less harmful to batteries etc.

Hey Gearhead,

I emailed Surefire about this and this is what they wrote;

"Sir,
The batteries should be OK at the temperature mentioned (140 F). If you have any further questions do not hesitate to write back or call us at 1-800-828-8809. We are dedicated to providing world-class customer service and welcome future inquiries or comments.

SureFire Technical Support "

I keep a thermometer in my glovebox and the Sacramento summer sun can get the cab temp of my truck up to 140 F.

Someone here did a study awhile back about heat and battery life. CR123 shelf life is reduced to 2 years when stored at the above mentioned temp according to the author.

kelmo

We here in Malaysia have no such problems with the heat. Laminating your windows with window tint could also help reduce most of the UV penetrating into your car which then makes the insides much cooler, less harmful to batteries etc.

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Most car windows these days come with UV filtering, and glass inherently filters a lot of UV anyway. The biggest problem with windows is that short-wave IR and visible light can radiate in, and heat up the upholstery. That heated up upholstery then radiates heat back, but at a longer wavelength IR that is reflected by the windows (thus trapped inside the car).

Usually the biggest glass surface area is the windshield -- buying a big reflective screen to put up against the windshield, and then parking with the windshield facing the sun has worked wonders for my Civic, which doesn't have any sort of aftermarket window tinting (in CA, tinting is only allowed on the back windows, -- and I've avoided doing it as I find the "limo" look with dark windows in the back and clear windows in the front tacky)

The thermos/cold box is a good idea though, not just for flashlights, but all sorts of electronic gizmos and such that have LiIon batteries that may be sensitive to excessive heat buildup. Another thing I've been doing is storing my spare batteries in the refrigerator -- as this slows down the self-discharge significantly (especially significant with NiMH).

FWIW, I have taken a 6P with Surefire batteries in a house fire where temperatures were around 400 degrees in some areas and I did not have a problem. YMMV
Dave

Sable said:

Alternative: Keep the light in a Thermos bottle. Seriously. Dewar flasks are excellent at keeping temperature differentials.

Click to expand...

Gah! another one of those "why-didn't-I-think-of-that" moments! Excellent Idea! I will most definately try this if I put the G2 in a car and have my microlight, another surefire (prolly new E1L) and my glotoob with me as EDC.
Have a good one!
Flash

i agree Cool the CAR kill 2 boyds with one stone.
worried about ya 300$ flashlight, and 3$ battery, when the $30,000 car stuff costs a lot more, and dies about as fast. all that plastic in cars, plus the uphulstry fading and stuff like that. prevent all of the heat as best as possible and you save the $300 light, the $30,000 car, and save gas by using the AC less when you get in and fire it up. plus you wont be as uncomfortable when getting in. plus think about all the electronics IN the car, that will love being a bit cooler, when you fire up the car, like the 4-4000W of heat pouring out of your stereo. if the stereo is already hot, turning it on will add more to the heat.
got a CD in the car? that laser diode will also appreciate starting up cooler.
what about ya GPS, and cell phone, also often using a li-poly battery that works better cooler.
only reason NOT to try and keep the whole car cooler, is if its snowing out

Sable said:

Shouldn't the glove box be a bit cooler? I lived in the desert for a while and it seemed like stuff in the glove compartment was usually a little less hot than the rest of the car, and we're talking 100+ degree days.

Click to expand...

I've found the opposite. With the sun hitting the dash the glovebox in my car gets hotter than the centre console which has no direct sun on it most of the time and is more isolated from the direct outside heat by being in the middle of the car. It probably varies from car to car though.

The thermos idea sounds good!

The main torch I leave in my car is a SL PP 4AA Lux. Apart from being a good light I like the idea of the vented body to release any pressure that might build up as temps increase. I keep Lithium AAs in it.

If you use a thermos, make sure it isn't the glass-lined type, or the flashlight rattling around inside may break it. Unfortunately, the glass-lined type are usually the best at insulating.

My car is white, and I just keep suck things in the trunk. even on the hottest days, when the dark interior of the car sucks in the heat, the trunk remains blissfully cool. Any light color paint should keep the trunk cool, and even a darker color will probably be much cooler in the trunk since there are no windows as the passenger compartment.